A conventional rod-in-tube (R-I-T) solid propellant grain design requires two casting operations, one for the rod portion of the propellant grain and one for the tube portion of the propellant grain. A mechanical support device is also required for the rod portion of the grain. The mechanical support device increases the rocket motor weight; however, regardless of the extra weight burden the R-I-T solid propellant grain design provides burning neutrality desirable for some opeations; therefore, it is a necessary burden to the system using it.
The elimination of extra weight of a non-contributing member for propulsion would be advantageous, particularly, if the burning neutrality can be retained.
Therefore, an object of this invention is to provide a Single Cast Rod-In-Tube (SCRIT) solid propellant rocket motor grain.
A further object of this invention is to provide a solid propellant rocket motor grain having a unique design that reduces the production time and cost while maintaining the symmetry, simpicity and burning neutrality of the conventional rod-in-tube (R-I-T) grain design.
Still a further object of this invention is to achieve a reduced rocket motor weight because of the design that does not require a mechanical support device for the rod portion of the grain.